A. Field of the Invention
The present invention relates to an imaging apparatus such as an endoscope or a monitor TV camera which comprises a solid-state imaging device in a camera head.
B. Description of the Prior Art
An endoscope, a so-called electronic scope, is known as a conventional imaging apparatus. In this endoscope, a solid-state imaging device (SID) is arranged in the distal end portion of an insertion section, and an optical image received by the light-receiving surface of the SID can be monitored through a camera control unit.
An endoscope comprising a camera head incorporating such an SID is disclosed in Japanese Patent Disclosure No. 60-208726. In an endoscope of this type, an SID chip is arranged to be perpendicular to the axis of an endoscope insertion section, and external terminals are randomly arranged on the rear surface of the SID. All the external terminals are connected to circuit boards mounting electrical parts. Conductive wire groups of a power cable connecting a camera control unit and the camera head, are connected to all the circuit boards mounting the electrical parts, and are also connected to the external terminals of the SID.
In an electrical signal processing section in the camera head in which external terminals are randomly arranged and all the terminals are connected to peripheral circuits as in the conventional SID, if the number of I/O signals is small and only several shield wires are connected like in a black-white SID, there is no problem. However, if several tens of shield wires must be connected, a considerably large space for connecting the SID and circuit boards and for connecting circuit boards and the shield wires is required, and the size of the peripheral circuit board becomes undesirably large. For this reason, the entire electrical signal processing section becomes bulky and prevents a compact camera head. In the endoscope, this undesirably causes an increase in outer diameter of the insertion section.